The present invention relates to a structure of a magnetic head slider for attaining high-density recording in a magnetic disk drive. In particular, the invention relates to a flying height controlling slider having a function of controlling the distance between a magnetic disk and a magnetic head.
A magnetic disk drive comprises a rotating magnetic disk and a slider having a magnetic read/write device constituting a magnetic head mounted thereon and supported by a suspension, in which the slider runs relatively on the magnetic disk to read and write magnetic information to the magnetic disk. The slider flies by the air edging film effect as an air lubrication bearing, so that the magnetic disk and the slider are not in direct solid contact with each other. To increase the recording density of the magnetic disk drive thereby increasing the capacity thereof or decreasing the size thereof, it is effective to decrease the distance between the slider and the magnetic disk, that is, the flying height of the slider thereby increasing the linear recording density.
Heretofore, the slider flying height has been designed to have a margin so that the slider does not come in contact with the disk even under the worst conditions while allowing for lowering of the flying height caused, for example, by fabrication variations, difference of the atmospheric pressure in the working circumstance, and the temperature difference in the working circumstance. The margin can be saved if a slider having a function of controlling the flying height on every individual head or in accordance with the working circumstance can be provided, whereby the flying height of the magnetic read/write device can be decreased greatly while the slider is prevented from coming into contact with the disk.
Patent document 1 (Japanese Patent Laid-open No. 5(1993)-20635) discloses a technique of providing a thin film resistor between a lower magnetic pole piece and an upper magnetic pole piece of an induction type thin film magnetic head and optionally energizing the resistor to heat thereby thermally expanding and protruding the top end of the magnetic pole piece to decrease the gap between the top end of the magnetic pole piece and the magnetic disk surface. Patent document 2 (Japanese Patent Laid-open No. 2003-168274) discloses a technique of providing a heat generation means at the rear portion of a writing head device and a reading head device thereby controlling the magnetic spacing.